I think he would benefit from a curriculum because he skips a lot of topics. For example, last year he was learning multiplication, and memorized a lot of the multiplication tables, but not all of them because he became interested in square roots. Same thing with division. And he found multiple digit addition and subtraction not to be very interesting, so I don't think he has mastered it completely (but he does.) He needs to master the basics, all of them, or his school is going to jump on the one skill he doesn't have as "proof" he doesn't need acceleration (even if he learns it the first time it is explained.)
